Mycophenolate mofetil may allow cyclosporine and steroid sparing in de novo heart transplant patients

BACKGROUND: Mycophenolate mofetil (MMF) provides superior prophylaxis against acute rejection when compared with azathioprine (AZA) in heart and renal transplantation. However, it remains unclear whether this results in improved survival or reduced morbidity after heart transplantation. METHOD: In a sequential study, 240 cardiac transplant patients were treated with either MMF (n=119) or AZA (n=121) both in combination with cyclosporine and corticosteroids after rabbit antithymocyte globulin induction. RESULTS: By protocol lower cyclosporine levels were targeted in the MMF group during the first year (e.g. 203+/-52 ng/mL MMF vs. 236+/-59 ng/mL AZA, P=0.0006 at 6 months). Patient survival at 1 year (82% MMF vs. 79% AZA, P=0.55) and at 3 years was similar in both groups. The cumulative probability of receiving antirejection treatment within 1 year was lower in the MMF group, as was biopsy-proven acute rejection with International Society of Heart and Lung Transplantation grade > or =3A (24% vs. 35%, P=0.03). The MMF group also had fewer episodes requiring cytolytic therapy (6% vs. 13%, P=0.04) and more patients had steroids withdrawn by 1 year (66% vs. 32%, P<0.001). Renal function was better in the MMF group with lower creatinine levels at 1 year (133+/-45 vs. 155+/-46 micromol/L, P=0.0004). Calculated creatinine clearance (Cockcroft and Gault formula) at 1 year was also better (MMF 74+/-32 mL/min vs. AZA 62+/-24 mL/min, P=0.004). CONCLUSION: Our results suggest that immunosuppression with MMF rather than AZA may allow lower cyclosporine levels, better renal function, and increased steroid weaning at 1 year while also achieving better control of acute rejection.